1. Field of the Invention
The claimed subject matter pertains to an enteral diet, i.e. oral or tube feed for patients with pulmonary disease.
2. Description of the Related Art
Two products are currently available for nutritional therapy for pulmonary disease patients. Pulmocare.TM. (Ross Laboratories), a high fat product, contains 16.7% (62.6 g/l) protein, 55.2% (92.1 g/l) fat, and 28.1% (105.7 g/l) carbohydrate. The sources of these macronutrients are casein, corn oil, and sucrose and hydrolyzed cornstarch, respectively. Ensure HN.TM. (Ross Laboratories) contains 16.7% (44.4 g/l) protein, 30.1% (35.5 g/l) fat, and 53.2% (141.2 g/l) carbohydrate. The sources of these macronutrients are casein and soy isolate, corn syrup and sucrose, and corn oil.
Researchers have studied the effects of short term enteral feeding on pulmonary patients. In particular, it has been found that nitrogen balance and muscle strength are improved in patients receiving either of two--Pulmocare.TM. (high fat) or Ensure HN.TM. (high carbohydrate). Dr. Goldstein, "The Metabolic Ventilatory and Functional Effects of Refeeding Malnourished Patients with Emphysema", dissertation, Columbia University.
Dr. Goldstein's work suggests that feeding with the high fat product, Pulmocare.TM., is preferable if one wishes to reduce ventilatory response. This study suggests that respiratory patients (primarily emphysema and COPD patients) are hypermetabolic with the unique characteristic of being unable to tolerate the large carbon dioxide loads associated with metabolism of carbohydrates. Thus, the increased caloric requirements of these patients must be fulfilled with lipid rather than carbohydrate. This aspect of these patients' metabolic requirements has been addressed in the formulation of Pulmocare.TM..
There are specific metabolic requireeents, however, that are not met by Pulmocare.TM.. A large part of the increased caloric requirement is associated with supporting the respiratory musculature and the work requirement to maintain the blood gases within normal physiologic limits. This is especially true with even the minor increase in exercise associated with normal daily activities. There is a specific need for a calorie source that is readily available to the respiratory muscle and a source of high quality protein to support and maintain muscle structure and function. There may also be specific micronutrient requirements.